Thirty-three-year-old hero-narrator Philippe Marlo, who previously worked in the district attorney’s office of Los Angeles, has now become a private detective and is investigating cases in which his clients are not interested in publicity. He is at the home of the millionaire Guy Sternwood, who informs Marlo that a certain Geiger blackmails his youngest daughter Carmen. In addition, the husband of his eldest daughter, Red Rygan, at one time the officer of Ira, who took part in the Dublin uprising, then disappeared, and then earned quite a bit by illegal selling of alcohol in America during the years of the dry law. Sternwood also reports that at one time his daughter Carmen was blackmailing someone Joe Brody and he had to pay the latter five thousand dollars.
Marlo sets up surveillance over the Geiger bookstore and comes to the conclusion that trade in second-hand and rare editions is just the roof for selling products that are clearly pornographic in nature. In the evening, Marlo begins to monitor the house of the Geiger, in which he discovers a car belonging to Carmen. Soon, shots are heard in the house. Penetrating inside, Marlo discovers the corpse of the owner and absolutely naked Carmen in a state of drug intoxication. Apparently, she posed for the camera of the owner.
Hurriedly delivering the girl to her father’s house, Marlo again returns to the house of the Geiger, but the corpse of the host disappears mysteriously. The next morning, Marlo learns that in the sea at the pier there was found a Sturnwood Buick, and in it there is the corpse of a man who worked as a chauffeur for the Sternwoods and, apparently, was in love with Carmen.
Resuming the observation of the Geiger bookstore, Marlo discovers that the pornographic goods are urgently transported to the apartment by Brody himself, whom Sternwood mentioned earlier. Returning home, he finds his older sister Carmen Vivien. She tries to understand the purpose of Marlo’s visit to their house on the eve, and in addition, reports that she was sent photos of naked Carmen and demand for a negative and prints of five thousand dollars. She is basically ready to get money – for example, the owner of the casino “Cypress” Eddie Mars, whose wife, according to rumors, and fled Redhead Regan.
Marlo goes to Brody. There is also a blonde who worked in the store Geiger. Marlowe reports that he knows everything about the Geiger business, and tells about
the role Brody played there, and about what Carmen showed on Brodie as the Geiger killer. At the height of the talks Carmen appears and tries to shoot Brody. She threatens to tell the truth about the death of the Geiger and requires photography. She grabs the revolver and shoots Brodie, but misses. She manages to be persuaded to go home, and Marlo gets photos. Thrown into a corner, Brodie admits that he took them from Taylor, whom he tracked down at Geiger’s house. He overtook him in a secluded place, and, deafening, took away the same photographs that he took from the Geiger, afterwards having shot him.
The clarification of relations is interrupted by a new bell at the door, and Brody, who has come out to be discovered, is mortally wounded by an unknown visitor. Marlow is soon on his trail. This is someone Lindgren, who worked in the Geiger store and associated with him homosexual relationships. Lindgren shot Brody, because he was sure that it was Brodie who killed his friend. Marlow leads him to the house of the Geiger, and he shows where the corpse is. As for Taylor, then, having shot Geiger in front of his beloved Carmen, and then losing his compromising photos after a clash with Brodie, he committed suicide by sending the car into the sea from the dock.
Formally, Marlo fulfilled his client’s order and figured out who had blackmailed him, but the professional excitement makes him try to find out what happened to Ryzhin Rigan. Eddie Mars, who showed little interest in the course of the police investigation of the disappearance of Rigan and his wife, categorically denied any involvement in this case. He assures Marlo that he did not kill Rigan, and he is inclined to believe him.
Returning to his home, Marlo finds in his bed completely naked Carmen. With great difficulty, he manages to expose this sex-obsessed person behind the door. The next day, Marlo draws attention that he “grazes” a man in a gray “plymouth.” It turns out that someone Harry Jones is ready for two hundred dollars to tell him some confidential data. He knows where the wife of Eddie Mars is currently hiding. According to him, she is in a secluded place forty miles from Los Angeles since Redhead Regan disappeared.
Marlo is willing to pay for information and promises to bring money in the evening at the address specified by Jones. Upon receipt of the fee, Jones promises to take Marlo to the same Agnes that she worked with Brody, and there already give him the exact address of Mona Mars. However, having appeared at the specified time in the specified place, Marlo discovers that Jones already has a guest. They are someone Canino, whom Eddie Mars occasionally uses as a killer. Both of them were terribly frightened by the contact between Jones and Marlo. Canino pulls Jones’ address from Agnes, and then treats him to a drink with cyanide and goes to deal with Agnes.
Marlo manages to get ahead of Canino. He meets with Agnes, and she, having received the required amount, informs him of the whereabouts of Mona Mars. Marlowe goes to where the wife of Mars and the mistress of the Red Rigana are hiding. He meets Canino. When Marlo comes to himself, he finds out that he is tightly tied to the sofa, and on his hands he has also handcuffed. With him in the room a blonde, the same Mona Mars, who was interested in him. She assures Marlo that Eddie has nothing to do with the disappearance of the Redhead Rigan, and then unties him and asks him to leave as quickly as possible. But Marlo leaves nearby – to the car left by him on highway, takes away therefrom the revolver and comes back. He does not doubt that Canino will return only to finish him and his boss’s wife.
Maneuver Marleau brings success. He manages to lure Canino from the house and shoot him, despite handcuffs.
Marlo is visiting old Sternwood again. He reproaches him for his initiative: after all, Marlo’s task was only to deal with the blackmailer, and not to search for the missing Rigan. He, however, with his usual straightforwardness declares that he knows better how to protect the interests of the client, and Geiger was just a small bipod, probing Sternwood for vulnerability. According to Marlo’s calculations, this vulnerable place was exactly Regan, and Sternwood was not worried about money and not because of his spoiled daughters. He just did not want to be deceived by a man who aroused his sincere sympathy.
After listening to this tirade, Sternvud instructs Marlo to continue the investigation. But Marlo is already close to unraveling. He encounters Carmen, who asks to be instructed to shoot her. He agrees, but only where they are not heard. He takes her to a private place she chooses, hands her a revolver and goes to install a target for shooting. Then she opens fire on him, and if Marlo had not prudently loaded the revolver with empty cartridges, he would not have carried out the investigation to the end.
After shooting all the cartridges, Carmen falls in a strong fit, and Marlo takes her home. There he meets Vivienne and tells her about the results of his experiment. Geiger blackmailed the general on the orders of Mars. And if he had agreed to pay, Eddie would have squeezed out a lot of money from him, since he knew what had happened to Ryzhin Rigan. He was murdered by Carmen Sternwood – apparently, in retaliation for rejecting her sexual harassment. Vivien, however, does not intend to shut herself up. She admits that she learned about Carmen’s deed and asked Mars to help hush things up. She did not doubt that at the first interrogation the feeble-minded Carmen would not have stood up and confessed, and that would have killed her father. Vivien understood that Eddie Mars would not leave her so easily, but she saw no other way. She waits anxiously for what price Marlo asks for silence. But he is not going to cash in on his gloomy discovery. He only demands that Vivien find a reliable psychiatric hospital for her sister, and with Eddie Mars he will figure it out and make sure that he does not bother Sternwood any more.